Antibiotic solution

ABSTRACT

An aqueous solution of a basic water-soluble antibiotic, stable to coloring and reduction in pH value is obtained by incorporating in the aqueous solution, a polyhydric alcohol selected from the group consisting of glycerin, propylene glycol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, and mannitol.

United States Patent Takenaga et al.

Sept. 9, 1975 ANTIBIOTIC SOLUTION Appl. No.: 213,222

[30] Foreign Application Priority Data Dec. 29, l970 Japan 46-121887[52] US. Cl. 424/181 [51] Int. Cl. A61K 31/71 [58] Field of Search424/181 [56] References Cited UNITED STATES PATENTS 3,616,243 l()/l97lKawasaki ct al 195/80 OTHER PUBLICATIONS Chemical Abstracts, 77:l30587x, (1972).

The Merck Index, 8th Ed, Merck & Co., Inc., Rahway, N..I., 1968, pp.210, 359, 434, 435, 644, 876, 877 and 1072.

Chemical Abstracts, 63: 10049b, (1965).

Primary Examiner-Jerome D. Goldberg Attorney, Agent, or Firm-Sughrue,Rothwell, Mion, Zinn and Macpeak [57] ABSTRACT An aqueous solution of abasic water-soluble antibiotic, stable to coloring and reduction in pHvalue is obtained by incorporating in the aqueous solution, a polyhydricalcohol selected from the group consisting of glycerin, propyleneglycol, ethylene glycol, diethylene glycol, triethylene glycol,polyethylene glycol, and mannitol.

4 Claims, No Drawings ANTIBIOTIC SOLUTION BACKGROI 'ND OF THEINVENTION 1. Field of the Invention As a stabilizer for preventing theaqueous solution of an antibiotic from being colored during preservationthereof, a sulfite such as sodium sulfite. sodium bisulfite, and sodiummetabisulfite is ordinarily used. How- The present invention relates toa process forprepar- 5 ever, as shown in Table 1, in which the coloringstabiling a stable solution of a basic water-soluble antibiotic, i f a17, aqueous l i f aminodeoxykanamycin Or the addltlomll Salts thereof,Such as y sulfate is illustrated, the addition of such a sulfite com-Chlmlde mtmte Phosphate and 306mm and the 11146, poundin an amount ofabout 0.1% provides no color Without bemg accompanied y dlscolorlmontprevention effect to the solution. However, when about Descrlpnon of theAn l 1% of sodium bisulfite or sodium metabisulfite is added Althoughthe effect of baslc Water-Soluble umlblto the solution, a colorprevention effect is observed. otic 3 t is tiot subcsitansially;variedthwhen it is dissobied in However, the addition of such aneffective amount of waer.i s'v n f f a l l s f g fi so i g the sulfitereduces the pH of the aqueous solution with iereo r ex b e or i is i f h5' CO the passage of time as shown in Table 2, in which the rownwi eassaeo i ,w

I I p f 5 1 F re T 6 variation ofthe pH ofa 1% aqueous solution ofaminocommereia va ue o t e so ution. or examp e,.w en deoxykanamycinSulfate is illustrated a 17( aqueous solution of fradiomyein sulfate orstrepl h h b T bl h H f tomycin sulfate is stored for 1 month at 37C.,the solu- Fm exdmp S 9 m t a Ove a t e 0 tion is clearly colored andalso when a 1% aqueous sothe 7 aqueous Solunon o.f ammt9dgoxykdnamycmlution of kanamycin sulfate or aminodeoxykanamycin g ll g s w 0 d g g5X2 l'g sulfate is stored for 2 months at 37C., the solution is e g 1 g grammgl re7uce 5 clearly colored. h 7 84: Stormfi or 21.21a S 2; r; 1f

Attempts for effectively preventing the occurrence of mmlths o c Q I ban the color in such solutions have not yet been found. mom respeuweThere is usually employed a method of storing the Thus, if the amount ofthe sulfite is increased for obaqueous solution under an oxygen freecondition by retaining a coloring prevention effect, the pH of theplacing the surrounding air with a nitrogen gas or placaqueous solutionis reduced to an undesirable extent. ing the same in a closed glassvessel. However, in case That is, for example, when applying, an eyedrop to the of eye drops or syrups to which the means of the nitromucousmembrane of the eye, it does not irritate the gen gas replacement orplacement in a closed glass veseye in a pH range of 4.5 to 9.0, but doesirritate when sel is hampered it is quite diflicult to prepare a stablethe pH approaches a value outside of this range, as resolution which canbe stored for a long period oftime ported in the Eight Edition, JapanPharmacopoeia, without exhibiting discoloration.* Section 1, Commentary,page A-l 10, published by the i'lhe term discoloration pertains to thecoloration ofan aqueous solu- Hirokawa Book CO tioii ot a water solubleantibiotic upon standing.

it has. therefore, been desirable to stabilize an aque- From the abovepoints, the reduction of the pH of an ous solution of an antibiotic.such as eye drops, ear aqueous solution of an antiobiotic is undesirableand drops. nasal drops. syrups. or injections in such a manfurther,because it is desirable to maintain the pH of ear nor as to preventdiscoloration. drops, nasal drops, and injections around neutral, the

Table 1 10' mg. ml. As Aniinotleo\ \kananiycin Free Base (UpJHlCI'UHSoptical density) Atlditne liiitial 2 months 2 months 2 months a month25C 37C 45"(. 00C.

NUHL t-0mm1i 0.000 0.021 (1.076 0.154 0.170 N;i .S(), 0 i'.; 0.010 0.0240.070 0.160 0.17: 0,5'1 0.030 0.0221 0 0x4 0.1s0 0.174 1.0 4 0.054 0.0740.1% 01s: 0.1xs \iiiHso. 0.10 0.020 0.033 0.072 0.174 0.170 0.5 0.01s0.024 0 020 0.020 0.020 1.0 0.016 0.024 0.02s 0.024 0.03: Nti .s.o,,0.1; 0.002 0.064 0.106 0.152 01.74 0 5 0.00s 0.012 0.034 0.024 0.0301.0m 0.012 0.010 0,013 0020 0.012

Table 2 It) [11:1 liictoi in! 11s \iiiinotleox kiiiianiycin Free BaseAdditive li|i1i.il l months 1 months I Il'liillll|\ a iiioiitli None(control) 0.": 0X0 (1.8: 1E0 N11 0.1; 0. 0 5.1M: 5.72 is. 0.5% 7.14 503(1.04 5.00 1.0 7.13 5.21 5.02 5.37 tsaHso, 0.10 (i. l) 6.08 (1.09 0.210.5; 5.60 2.50 2,50 1.15 1.00 5.52 3.20 2.15 1.00 Nt s o, 0.1 0.43 (MM6.08 0.35 0.5 5.4.1 2.3: 2.30 2.30 1.00 s is 203 10s 1.s0

Table 3 Dilution assay of aqueous solution of aminodcoxy kanamycinsulfate pH St. aureus (209p) 1;. coli (1AM I253) 24 hrs 48 hrs. 24 hrs.48 hrs. 5.0 20.0 20.0 20.0 20.0 6.0 5.0 5.0 5.0 5.0 7.0 1.3 1.3 (1.6 1.3

Lnit: microns gfml. Init: microns g'ml.

I'hat is. the inventors h.i\c dis'cm cred that a poly h dric alcoholselected from the group consisting of gly cerin. propylene glycol.ethylene glycol. diethylene glycol. tricthy lene glycol. polyethyleneglycol. and mannito] is quite effective for preventing the discoloration01 an aqueous solution of a basic water-soluble antibiotic. In addition.an aqueous solution of such an antibiotic containing a hydrophilicalcohol as the coloring preventing agent can be stored for a long periodof time without an attendant reduction in the pH value.

For example. after a 1" aqueous solution of aminodeoxykanamycin sulfatewas incorporated with glycerin or propylene glycol in accordance withthis inventiorl. in an amount shown in the following table and storedfor the period of time shown in the same table. the coloring state ofthe solution was observed. The results are shown in the following tabletogether with a control case.

Table '4 Additive Initial I months 2 months 1 months 1 month K. 3"(.not.

None (control) (1.000 (1.021 (1.070 (1.154 (1.1( (ilycerin 5' (1.0111(1.001 .01: (1.0(1b (1.010 1o, (moo (too-1 (1,0(1h (tooA (1.(1U.

:(I', (1.00: I1.(1(1r (1,012 (1.(1l-l ll1 Propylene glycol 5'1 (1.0(1-1oolo (1.012 o olo (1.014 N l(1"4 (1.01: (1.010 ooos (l.(1(1.\ (L01: 2o;(Loos oolo ooos (toll ooln Furthermore. a sulfite is liable to beoxidized and thus when the sulfite is incorporated in the aqueous so-Also. the change in pH of the solution was observec and the results areshown in the following table:

lution of an antibiotic. the sulfite in the solution may be oxidizedwith the passage of time. i

As mentioned above. the conventional method of employing the sulfite asa stabilizer for preventing the discoloration of an aqueous solution ofa basic watersoluble antibiotic is accompanied with a reduction in thepH of the solution. which in turn. results in the reduction in theactivity of the antibiotic. Therefore. the added amount of sulfite islimited to such a small amount that no reduction in pH of the solutionis observed. This is usually less than about (1.5%. which gives aninsufficient stabilization effect for preventing discoloration of thesolution as reported in Yakkyoku (Journal of Practical Pharmacy); Vol.21. page 477. 1970.

SUMMARY OF THE INVENTION Therefore. as the results of variousinvestigations. the in\ entors have discovered effective discolorationpreventing agcnts different from the conventional ty pc and havesucceeded in. based on this discovery. producing a stable aqueoussolution of a basic water-soluble antibiotic. which is not discolored(colored) with the passage of time.

DETAILED DESCRIPTION OF THE INVENTION The mechanism by which such apolyhydric alcohol provides this excellent effect has not yet been determined; however. on considering the fact that when other polyhydricalcohols. other than those mentioned above. such as diethylene glycolmonoethyl ether and sorbitol are employed as a stabilizer for an aqueousso lution of a water soluble antibiotic. the effect attained.

as above. is not obtained. This ould indicate. that the selection of thepolyhydric alcohol is critical and the mechanism of action is specific.

Therefore, according to the present invention, an aqueous solution of abasic water-soluble antibiotic stable to coloring is obtained byincorporating a polyhydric alcohol selected from the group consisting ofglycerin, propylene glycol, ethylene glycol, diethylcne glycol,triethylene glycol, polyethylene glycol, and mannitol and in an aqueoussolution of a gasic water-soluble antibiotic, such as fradiomycin,streptomycin, kanamycin, aminodeoxykanamycin, kasugamycin, gentamicin,paromomycin, or an acid-addition salt of such an antibiotic, e.g., asulfate, a hydrochloride, a nitrate, a phosphate, or an acetate.

There is no particular limit as to the amount of the polyhydric alcoholemployed in this invention; however, the amount normally employed rangesfrom 1-10%-. The aqueous solution of the basic watersoluble antibioticcontaining a small amount of the polyhydric alcohol according to thepresent invention can be stably stored for a long period of time withoutbeing accompanied by discoloration to a brown color or other color. Inaddition, a reduction in the pH thereof when the aforementioned solutionis storedin a glass vessel having a properstopper or in an air-tightclosable synthetic resin vessel without the presence of nitrogen gasreplacement or a glass closed vessel, such as a glass ampoule or vialisnot observed.

By the inventors experiments, a 1% aqueous solution ofaminodeoxykanamycin sulfate containing 2% glycerin prepared bydissolving l g. of aminodeoxykanamycin and 2 g. of glycerin in water toform 100 ml. of the solution was placed in a synthetic resin vessel andpreserved for 21 days at 60C. Thereafter when the absorbance of thesolution showing the colored extent of the solution was measured at 450m.,u., the absorbance was 0.014. On the other hand, when the absorbancewas measured at 450 m.p.. of a 1% aqueous solution ofaminodeoxykanamycin not containing glycerin after storing the solutionunder the same conditions as above, the absorbance was 0. l 72. When theabsorbance of the solution was 0.014 as in the case of adding glycerinethereto, the coloring of the solution was not observed by the naked eye,but when the absorbance of the solution was 0.172 as in the case ofadding no glycerin, it was clearly observed that the solution wascolored a yellow brown.

Moreover, according to the inventors experiments, the pH of a 1% aqueousaminodeoxykanamycin sulfate solution containing sodium bisulfateprepared by dissolving 1 g. of aminodeoxykanamycin and 1 g. of sodiumbisulfate in water to form 100 ml. of the solution was 5.5 immediatelyafter the preparation thereof, but when the solution was preserved forone week at room temperature, the pH of the solution was reduced to 2.3.On the other hand, when the polyhydric alcohol of this invention wasadded to the aqueous solution according to the present invention inplace of the sulfite, the pH of the solution was scarcely reduced withthe passage of time. That is, the pH of a 1% aqueous aminodeoxykanamycinsulfate solution containing 2% glycerin prepared by dissolving l g. ofaminodeoxykanamycin and 2 gv of glycerin in water to form 100 ml. of thesolution was 6.7 immediately after the preparation thereof and when thesolution was stored for one Week at room temperature, the pH of thesolution remained 6.7.

Moreover, when the above-mentioned polyhydric alcohol is incorporated inan aqueous solution of the basic watersoluble antibiotic, theanti-bacterial activity LII thereof is not degraded. For example,according to the inventors experiments, the anti-bacterial activity of a1% aminodeoxykanamycin sulfate containing 2% glycerin after preservationfor 21 days at 60C. was of the activity of the solution immediatelyafter the preparation thereof.

A better understanding of the present invention will be attained fromthe following examples, which are merely illustrative and not limitativeof the present invention.

EXAMPLE 1 A mixture of 1 g. of fradiomycin sulfate and 2 g. of glycerinwas dissolved in water to provide 100 ml. of the aqueous solution. Forcomparison, a 1% aqueous fradiomycin sulfate solution not containingglycerin was prepared.

Each of the 1% aqueous fradiomycin sulfate solution containing 2%glycerin and the 1% aqueous fradiomycin sulfate solution not containingglycerin (prepared above) was placed in a synthetic resin vessel andafter the solution was stored for 21 days at 60C the absorbance of thesolution at 450 m.,u. showing the colored extent of the solution wasmeasured. The results indicate that the absorbance of the 1% fradiomycinsulfate solution containing 2% glycerin was 0.077, while the absorbanceof the 1% aqueous fradiomycin sulfate solution containing no glycerinwas 0.198. Thus, the coloring of the 1% aqueous fradiomycin sulfatesolution containing 2% glycerin according to the present invention wasprevented.

EXAMPLE 2 A mixture of l g. of fradiomycin sulfate and 2 g. of propyleneglycol was dissolved in water to provide 100 ml. of the solution andalso, for comparison, a 1% aqueous fradiomycin sulfate solutioncontaining no propylene glycol was prepared as a control sample.

When each of the l% aqueous fradiomycin sulfate solution containing 2%propylene glycol and the 1% aqueous fradiomycin solution containing nopropylene glycol (prepared above) was tested as in Example 1, theabsorbance of the 1% aqueous fradiomycin sulfate solution containing 2%propylene glycol was 0.065, while the absorbance of the 1% aqueousfradiomycin sulfate solution containing no propylene glycol was 0.198.Thus, the coloring of the 1% aqueous fradiomycin sulfate solutioncontaining 2% propylene glycol was prevented.

EXAMPLE 3 A mixture of 1 g. of fradiomycin sulfate and each of thepolyhydric alcohols shown in Table 6 below, in the amount shown therein,was dissolved in water to provide 100 ml. of the aqueous solution. Also,for compar ison, a 1% aqueous fradiomycin sulfate solution containing nopolyhydric alcohol was prepared as a control sample.

When each of the 1% aqueous fradiomycin sulfate solution containing thepolyhydric alcohol and the 1% aqueous fradiomycin sulfate solutioncontaining no polyhydric alcohol (prepared above) was tested as inExample 1, the results shown in the following table were obtained. Theresults clearly establish that discoloration was prevented in theaqueous solutions of the antibiotic containing the polyhydric alcohols.

A mixture of l g. of streptomycin sulfate and g. of glycerin wasdissolved in water to provide 100 ml. of the aqueous solution and forcomparison, a 1% aqueous streptomycin sulfate solution containing noglycerin was also prepared as a control sample.

When each of the 1% aqueous streptomycin sulfate solution containing 5%glycerin and 1% aqueous streptomycin sulfate solution containingnoglycerin (prepared above) was tested as in Example 1. the absorbanceof the 1% aqueous streptomycin sulfate solution containing 5% glycerinwas 0.098. while the absorbance of the 1% aqueous streptomycin sulfatesolution containing no glycerin was 0.183. Thus. the coloring of the 1%streptomycin sulfate solution containing 5% glycerin was prevented.

EXAMPLE 5 hols of this invention.

Table 7 Additive and the amount Ahsorbanee at 450 m. .1..

None (control) 0.183 Glycerin ZJ 0.173 Glycerin 10% 0.154 Propyleneglycol 5% 0,094 Polyethylene glycol 1' 0.084 Mannitol 1% 0.125

EXAMPLE 6 A mixture of l g. of kanamycin sulfate and 5 g. of glycerinwas dissolved in water to provide 100 ml. of the aqueous solution. Forcomparison, a 1% aqueous kanamycin sulfate solution containing noglycerin was prepared as a control sample.

When each of the 1% aqueous kanamycin sulfate solution containing 5%glycerin and the 1%. aqueous kanamycin sulfate solution containing noglycerin (prepared above) was tested as in Example 1, the absorbanceofthe 1% aqueous kanamycin sulfate solution containing 5% glycerin was0.006, while the absorbance of the 1% aqueous kanamycin sulfate solutioncontaining no glycerin prepared as a control sample was 0.063. The aboveresults show that coloring of the 1% aqueous kanamycin sulfate solutioncontaining 5% of glycerin was prevented.

EXAMPLE 7 A mixture of l g. of kanamycin sulfate and each of the variouspolyhydric alcohols shown in Table 8, in the amount shown therein, wasdissolved in water to make ml. of the aqueous solution. For comparison,a 1% aqueous kanamycin sulfate solution containing no polyhydric alcoholwas prepared as a control sample.

When each of the 1% aqueous kanamycin sulfate solution containing thepolyhydric alcohol and the 1% aqueous kanamycin sulfate solutioncontaining no polyhydric alcohol was tested as in Example 1. the resultsshown in obtained. 8 were obtaianed, which demonstrate that the coloringof the'aqueous solutions of the antibiotics containing the polyhydricalcohols was prevented.

Table 8 Additive and the amount Absorbance at 450 m. ;1..

A mixture of 1 g. of aminodeoxykanamycin sulfate and 2 g. of glycerinwas dissolved in water to make 100 m1. of the aqueous solution and alsofor comparison, a 1% aqueous aminodeoxykanamycin sulfate solutioncontaining no glycerin was prepared as a control samp When each of the1% aqueous aminodeoxykanamycin sulfate solutions containing 2% glycerinand the 1% aqueous aminodeoxykanamycin sulfate solution containing noglycerin was tested as in Example 1. the absorbance of the 1% aqueousaminodeoxykanamycin sulfate solution containing 2% glycerin was 0.014,while the absorbance of the 1% aqueous solution containing no glycerinwas 0.172. The results indicate that the coloring of the 1% aqueousaminodeoxykanamycin sulfate solution containing 2% glycerin wasprevented.

EXAMPLE 9 A mixture of 1 g. of aminodeoxykanamycin sulfate and each ofthe various polyhydric alcohols shown in Table 9. in the amount showntherein, was dissolved in water to make 100 ml. of the aqueous solutionand also for the comparison. a 1% aqueous aminodeoxykanamycin sulfatesolution containing no polyhydric alcohol was prepared as a controlsample.

When each of the 1% aqueous aminodeoxykanamycin sulfate solutionscontaining the polyhydric alcohol and the 1% aminodeoxykanamycin sulfatesolution containing no polyhydric alcohol was tested as in Example 1,the results shown in Table 9 were obtained, which proved that thecoloring of the aqueous solutions of the antibiotic containing thepolyhydric alcohols was prevented.

Although the present invention has adequately and extensively beendiscussed in the foregoing disclosure and examples included therein, itis readily apparent that various changes and modifications can be madewithout departing from the spirit and scope thereof.

What is claimed is:

1. An aqueous antibiotic composition consisting essentially of anantibiotic effective amount of aminodeoxykanamycin, l 10% of glycerinewith the balance of the aqueous composition being water.

2. An aqueous antibiotic composition consisting essentially of anantibiotic effective amount of aminodeoxykanamycin, l 10% of propyleneglycol, with the balance of the aqueous composition being water.

3. An aqueous antibiotic composition consisting essentially of anantibiotic effective amount of aminodeoxykanamycin, l 10% ofpolyethylene glycol, with the balance of the aqueous composition beingwater.

4. An aqueous antibiotic composition consisting essentially of anantibiotic effective amount of aminodcoxykanamycin, l 10% of mannitol,with the balance of the aqueous composition being water.

1. AN AQUEOUS ANTIBIOTIC COMPOSITION CONSISTING ESSENTIALLY OF ANANTIBIOTIC EFFECTIVE AMOUNT OF AMINODEOXYKANAMYCIN, 1 -10% OF GLYCERINEWTH THE BALANCE OF THE AQUEOUS COMPOSITION BEING WATER.
 2. An aqueousantibiotic composition consisting essentially of an antibiotic effectiveamount of aminodeoxykanamycin, 1 - 10% of propylene glycol, with thebalance of the aqueous composition being water.
 3. An aqueous antibioticcomposition consisting essentially of an antibiotic effective amount ofaminodeoxykanamycin, 1 - 10% of polyethylene glycol, with the balance ofthe aqueous composition being water.
 4. An aqueous antibioticcomposition consisting essentially of an antibiotic effective amount ofaminodeoxykanamycin, 1 - 10% of mannitol, with the balance of theaqueous composition being water.